diff options
Diffstat (limited to 'synapse/handlers/federation.py')
| -rw-r--r-- | synapse/handlers/federation.py | 204 |
1 files changed, 153 insertions, 51 deletions
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 60b97b140e..6350a4c204 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -39,11 +39,12 @@ from synapse.events.validator import EventValidator from synapse.util import unwrapFirstError, logcontext from synapse.util.metrics import measure_func from synapse.util.logutils import log_function -from synapse.util.async import run_on_reactor, Linearizer +from synapse.util.async import Linearizer from synapse.util.frozenutils import unfreeze from synapse.crypto.event_signing import ( compute_event_signature, add_hashes_and_signatures, ) +from synapse.state import resolve_events_with_factory from synapse.types import UserID, get_domain_from_id from synapse.events.utils import prune_event @@ -89,7 +90,9 @@ class FederationHandler(BaseHandler): @defer.inlineCallbacks @log_function - def on_receive_pdu(self, origin, pdu, get_missing=True): + def on_receive_pdu( + self, origin, pdu, get_missing=True, sent_to_us_directly=False, + ): """ Process a PDU received via a federation /send/ transaction, or via backfill of missing prev_events @@ -103,8 +106,10 @@ class FederationHandler(BaseHandler): """ # We reprocess pdus when we have seen them only as outliers - existing = yield self.get_persisted_pdu( - origin, pdu.event_id, do_auth=False + existing = yield self.store.get_event( + pdu.event_id, + allow_none=True, + allow_rejected=True, ) # FIXME: Currently we fetch an event again when we already have it @@ -161,14 +166,11 @@ class FederationHandler(BaseHandler): "Ignoring PDU %s for room %s from %s as we've left the room!", pdu.event_id, pdu.room_id, origin, ) - return + defer.returnValue(None) state = None - auth_chain = [] - fetch_state = False - # Get missing pdus if necessary. if not pdu.internal_metadata.is_outlier(): # We only backfill backwards to the min depth. @@ -223,26 +225,60 @@ class FederationHandler(BaseHandler): list(prevs - seen)[:5], ) - if prevs - seen: - logger.info( - "Still missing %d events for room %r: %r...", - len(prevs - seen), pdu.room_id, list(prevs - seen)[:5] + if sent_to_us_directly and prevs - seen: + # If they have sent it to us directly, and the server + # isn't telling us about the auth events that it's + # made a message referencing, we explode + raise FederationError( + "ERROR", + 403, + ( + "Your server isn't divulging details about prev_events " + "referenced in this event." + ), + affected=pdu.event_id, ) - fetch_state = True + elif prevs - seen: + # Calculate the state of the previous events, and + # de-conflict them to find the current state. + state_groups = [] + auth_chains = set() + try: + # Get the state of the events we know about + ours = yield self.store.get_state_groups(pdu.room_id, list(seen)) + state_groups.append(ours) + + # Ask the remote server for the states we don't + # know about + for p in prevs - seen: + state, got_auth_chain = ( + yield self.replication_layer.get_state_for_room( + origin, pdu.room_id, p + ) + ) + auth_chains.update(got_auth_chain) + state_group = {(x.type, x.state_key): x.event_id for x in state} + state_groups.append(state_group) + + # Resolve any conflicting state + def fetch(ev_ids): + return self.store.get_events( + ev_ids, get_prev_content=False, check_redacted=False + ) - if fetch_state: - # We need to get the state at this event, since we haven't - # processed all the prev events. - logger.debug( - "_handle_new_pdu getting state for %s", - pdu.room_id - ) - try: - state, auth_chain = yield self.replication_layer.get_state_for_room( - origin, pdu.room_id, pdu.event_id, - ) - except Exception: - logger.exception("Failed to get state for event: %s", pdu.event_id) + state_map = yield resolve_events_with_factory( + state_groups, {pdu.event_id: pdu}, fetch + ) + + state = (yield self.store.get_events(state_map.values())).values() + auth_chain = list(auth_chains) + except Exception: + raise FederationError( + "ERROR", + 403, + "We can't get valid state history.", + affected=pdu.event_id, + ) yield self._process_received_pdu( origin, @@ -320,11 +356,17 @@ class FederationHandler(BaseHandler): for e in missing_events: logger.info("Handling found event %s", e.event_id) - yield self.on_receive_pdu( - origin, - e, - get_missing=False - ) + try: + yield self.on_receive_pdu( + origin, + e, + get_missing=False + ) + except FederationError as e: + if e.code == 403: + logger.warn("Event %s failed history check.") + else: + raise @log_function @defer.inlineCallbacks @@ -458,6 +500,47 @@ class FederationHandler(BaseHandler): @measure_func("_filter_events_for_server") @defer.inlineCallbacks def _filter_events_for_server(self, server_name, room_id, events): + """Filter the given events for the given server, redacting those the + server can't see. + + Assumes the server is currently in the room. + + Returns + list[FrozenEvent] + """ + # First lets check to see if all the events have a history visibility + # of "shared" or "world_readable". If thats the case then we don't + # need to check membership (as we know the server is in the room). + event_to_state_ids = yield self.store.get_state_ids_for_events( + frozenset(e.event_id for e in events), + types=( + (EventTypes.RoomHistoryVisibility, ""), + ) + ) + + visibility_ids = set() + for sids in event_to_state_ids.itervalues(): + hist = sids.get((EventTypes.RoomHistoryVisibility, "")) + if hist: + visibility_ids.add(hist) + + # If we failed to find any history visibility events then the default + # is "shared" visiblity. + if not visibility_ids: + defer.returnValue(events) + + event_map = yield self.store.get_events(visibility_ids) + all_open = all( + e.content.get("history_visibility") in (None, "shared", "world_readable") + for e in event_map.itervalues() + ) + + if all_open: + defer.returnValue(events) + + # Ok, so we're dealing with events that have non-trivial visibility + # rules, so we need to also get the memberships of the room. + event_to_state_ids = yield self.store.get_state_ids_for_events( frozenset(e.event_id for e in events), types=( @@ -493,7 +576,20 @@ class FederationHandler(BaseHandler): for e_id, key_to_eid in event_to_state_ids.iteritems() } + erased_senders = yield self.store.are_users_erased( + e.sender for e in events, + ) + def redact_disallowed(event, state): + # if the sender has been gdpr17ed, always return a redacted + # copy of the event. + if erased_senders[event.sender]: + logger.info( + "Sender of %s has been erased, redacting", + event.event_id, + ) + return prune_event(event) + if not state: return event @@ -1371,8 +1467,6 @@ class FederationHandler(BaseHandler): def get_state_for_pdu(self, room_id, event_id): """Returns the state at the event. i.e. not including said event. """ - yield run_on_reactor() - state_groups = yield self.store.get_state_groups( room_id, [event_id] ) @@ -1403,8 +1497,6 @@ class FederationHandler(BaseHandler): def get_state_ids_for_pdu(self, room_id, event_id): """Returns the state at the event. i.e. not including said event. """ - yield run_on_reactor() - state_groups = yield self.store.get_state_groups_ids( room_id, [event_id] ) @@ -1446,11 +1538,20 @@ class FederationHandler(BaseHandler): @defer.inlineCallbacks @log_function - def get_persisted_pdu(self, origin, event_id, do_auth=True): - """ Get a PDU from the database with given origin and id. + def get_persisted_pdu(self, origin, event_id): + """Get an event from the database for the given server. + + Args: + origin [str]: hostname of server which is requesting the event; we + will check that the server is allowed to see it. + event_id [str]: id of the event being requested Returns: - Deferred: Results in a `Pdu`. + Deferred[EventBase|None]: None if we know nothing about the event; + otherwise the (possibly-redacted) event. + + Raises: + AuthError if the server is not currently in the room """ event = yield self.store.get_event( event_id, @@ -1459,20 +1560,17 @@ class FederationHandler(BaseHandler): ) if event: - if do_auth: - in_room = yield self.auth.check_host_in_room( - event.room_id, - origin - ) - if not in_room: - raise AuthError(403, "Host not in room.") - - events = yield self._filter_events_for_server( - origin, event.room_id, [event] - ) - - event = events[0] + in_room = yield self.auth.check_host_in_room( + event.room_id, + origin + ) + if not in_room: + raise AuthError(403, "Host not in room.") + events = yield self._filter_events_for_server( + origin, event.room_id, [event] + ) + event = events[0] defer.returnValue(event) else: defer.returnValue(None) @@ -1751,6 +1849,10 @@ class FederationHandler(BaseHandler): min_depth=min_depth, ) + missing_events = yield self._filter_events_for_server( + origin, room_id, missing_events, + ) + defer.returnValue(missing_events) @defer.inlineCallbacks |